A few years ago, Jill Rigby Garner received an email from a graduate student asking for her help with a book he had written. After reading the entire manuscript, Garner thought the subject matter held a lot of promise but that the book wasn’t ready for publication. She wrote him back, explaining what he’d need to do to draft a book proposal for an agent.

“I spent a considerable amount of time explaining the process, sent a detailed document on how to write a nonfiction book proposal, and offered help along the way in his preparation of the proposal,” says Garner, author of the book “Raising Respectful Children in a Disrespectful World” and founder of Manners of the Heart, which teaches children, parents and business professionals how to increase respectfulness in daily communication.

His response: “Oh, I understand. You don’t want to really help me. You want me to do all the work.” (Mike drop.)

Garner was speechless. But due to her line of work, she’s about 150 percent more polite than the average person, who would have likely fired back an expletive-filled response. (Garner opted not to respond.)

Whether they’re hoping to get a job, some advice or help on a school project, many younger millennials seem to have missed the memo on how to network without irritating the people who are in a position to help. After all, it’s only networking if you’re successful at it.

To be fair, any younger generation is always going to be subjected to a certain degree of “Kids these days!” muttered by their workplace elders.

Millennials are notoriously bad at making eye contact, a key networking skill.Shutterstock.com

Still, there’s a lot of truth behind these stereotypes. And millennials seem to have helped themselves to an extra portion at the entitlement buffet (which is all-you-can-eat, obviously, because it’s your right). A recent survey found 71 percent of American adults consider millennials “selfish” and 65 percent find them “entitled.”

“They’ve grown up in an atmosphere of instant gratification, instant information, and one that’s very child-centered,” says Garner. “There’s an expectation on their part that of course you’ll respond to them.”

E is for Experience: Others have it — you don’t. Your time in the sun will come. But right now, you and the person you’re contacting are not equals — chances are they’ve worked hard to get to where they are. Show some awareness and respect for that, and things should go really well.

E is also for Eye Contact: Millennials often have a hard time with eye contact — an absolute deal-breaker in an interview. “The reason this is an issue is because we live looking down [at our devices],” says Garner, who says she is often approached by business owners who ask, “How can you teach my 20-something employees eye contact?”

Garner will have young employees conduct staring contests with each other, forcing them to look at each other without laughing. “It’s a silly thing, but it’s amazing how it works,” she says.

A handwritten thank-you note goes a long way.Shutterstock.com

G is for Gratitude: Gratitude goes a long way — and costs absolutely nothing. When you’re thankful for the time someone gives you in answering your questions, they’re more likely to help you out down the road because they’re well-disposed toward you. It’s a mercenary way to look at it, but it’s true.

And call it passé, but nothing stands out like an old-fashioned thank-you note. “Follow-through is everything,” explains Garner. “It takes more time to craft a handwritten note. The least you can do when someone has given you their time is take five or 10 minutes to express gratitude and respect.”

R is for Request: Read over your email before you send it and ask: Does this sound more like a request — or a ransom note? Avoid the term “ASAP” at all costs, and make sure your message contains a please and thank you (seems like a given, but you’d be surprised).

And take care that your message is properly formal, even if you’re sending it over social media. Sites like Facebook make powerful people easier to get in touch with, but that doesn’t mean it’s OK to approach them like a stranger at a rowdy bar.

T is for Time: Remember that the person you’re contacting isn’t your parent or your teacher. In other words: They have no good reason (other than courtesy or generosity) to respond. So make sure any email or phone call comes from a place of respect for their time. “Keep an understanding that everyone’s busy today, and [you’re] asking someone to give up their time,” says Garner.

And for those millennials not making these mistakes? Keep it up — you guys have no idea how much you stand out!